Long-Term Water Saturation of Asphalt Binder Based on Fly Ash

DOI

10.2991/isees-18.2018.61How to use a DOI?

Keywords

fly ash from power plants, asphalt binder, water saturation, water resistance, new phases

Abstract

The use of fly ash from power plants as a component of paving asphalt concrete has been studied by many scientists for over 100 years. However, there are conflicting data of their effect on properties of composites. The reason for this may be insufficient understanding of the role of fly ash composition, dispersity, structure and features of the structure formation process in asphalt compositions. The problem should be realized complexly. The current paper presents the detailed investigation of changes in the composition and structure of asphalt binder, occurred under continuously water saturation. Experimental studies show the asphalt composite from the mixture of bitumen, and high-calcium fly ash (FA1) is characterized by a significant decrease in the strength characteristics, an increase in volume of absorbed water and volume of specimens under long-term water saturation. The author have found that the reason for this is low adhesion of organic binder to surface of fly ash particles, therefore the bituminous film flushes, the active minerals of fly ash, such as tricalcium aluminate, lime, portlandite, anhydrite, react with water and form new phases of ettringite, calcite and gypsum, that makes the structure less compact. Low-calcium fly ash (FA2) with the best adhesion to bitumen forms asphalt binder during long-term water saturation the composite is characterized by low dynamics of increasing water adsorption and reducing of strength. The structure of composite material is more stable in comparison with other compositions. Thus, the composition and adsorption capacity significantly affect water resistance of composites.

Copyright

© 2018, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Mikhail Sergeevich Lebedev
AU  - Natalia Ivanovna Kozhukhova
PY  - 2018/12
DA  - 2018/12
TI  - Long-Term Water Saturation of Asphalt Binder Based on Fly Ash
BT  - Proceedings of the International Symposium “Engineering and Earth Sciences: Applied and Fundamental Research” (ISEES 2018)
PB  - Atlantis Press
SP  - 316
EP  - 320
SN  - 2352-5401
UR  - https://doi.org/10.2991/isees-18.2018.61
DO  - 10.2991/isees-18.2018.61
ID  - Lebedev2018/12
ER  -